This invention relates generally to mine ventilation and, more particularly, to mine doors and mine stoppings.
So-called xe2x80x9cstoppingsxe2x80x9d are widely used in mines to stop off the flow of air in passageways in the mines, a xe2x80x9cstoppingxe2x80x9d generally being a masonry (e.g., concrete block) or metal wall installed at the entrance of a passageway to block flow of air therethrough. Such stoppings are typically provided with a doorway or opening and a door therein for occasional access to the blocked-off passageway. This arrangement is satisfactory under usual conditions when the stopping should prevent the passage of air through the passageway. In some conditions, however, high pressure concussive air is forced against the stopping and door. This may occur, for instance, in longwall mining where a large roof can collapse very rapidly and displace a large amount of air, thereby creating a shock wave of high pressure concussive air. Likewise, a mine blast will also force high pressure concussive air against the stopping and the door. In conventional stopping arrangements, the concussive air cannot escape through the stopping without causing significant damage to the stopping, the door or both.
Moreover, prior art stoppings are constructed generally perpendicular to the direction of air flow through the passageway. This construction is not optimal for decreasing the stress on the stopping caused by the concussive air.
Among the several objects and features of the present invention may be noted the provision of an improved mine stopping having a door which seals an opening in the stopping; the provision of such a stopping wherein the door can swing open in either of two directions to avoid damage to the stopping due, for example, to concussive air generated by longwall mining or by a mine blast; and the provision of such a stopping which is effective in controlling mine ventilation.
Further among the several objects and features of the present invention may be noted the provision of a mine stopping which may be installed in a mine passageway so as to reduce dynamic air pressure exerted on the stopping; the provision of such a mine stopping which is less likely to be damaged by concussive air; and the provision of such a mine stopping which is effective in controlling mine ventilation and which is economical to manufacture.
Briefly, this invention is directed to a mine stopping comprising a wall extending across a passageway in a mine to close the passageway. The wall has an opening therein. A door is hinged adjacent the opening for swinging between a closed position in which the door closes the opening to inhibit the passage of air therethrough, a first open position in which the door is swung in one direction away from the closed position, and a second open position in which the door is swung in an opposite direction away from the closed position. The door is movable to either of the first and second open positions when the door is subjected to substantial concussive air pressure thereby to permit concussive air to pass through the opening in both directions.
In another aspect of the invention, a swinging door system for closing an opening in a mine stopping comprises a door hinged adjacent the opening for swinging between a closed position in which the door closes the opening to inhibit the passage of air therethrough, a first open position in which the door is swung in one direction away from the closed position, and a second open position in which the door is swung in an opposite direction away from the closed position. The door is movable to either of the first and second open positions when subjected to substantial concussive air pressure thereby to permit concussive air to pass through the opening in both directions.
In yet another aspect of the present invention, a mine stopping is installed in a mine passageway having air flowing through the passageway in a first direction. The mine stopping comprises a rigid wall extending across the passageway to close it, and an opening in the wall to permit the passage of air therethrough for regulating the airflow. The wall extends between the opening and one side of the passageway at an oblique angle with respect to the direction of air flow through the passageway whereby air flowing through the passageway strikes the wall at the oblique angle thereby to reduce the dynamic air pressure exerted on the wall.
Other objects and features of the present invention will be in part apparent and in part pointed out hereinafter.